Originally Published in Herptile
- Journal of the International Herpetological Society, June 1994, 19
(2) pp. 61-66.

General Information;

Having resided in Melbourne for the
last 8 years, I've been unable to observe first-hand the effects of recent
bushfires on Sydney's herpetofauna (Melbourne
is about 890 km by road from Sydney). However, as a former long-term resident
of the Sydney area I am familiar with the scenario presented by bushfires
in and around Sydney. Speaking to people from Sydney and reading media
reports, the damage as a result of these most recent fires has been substantial.

The statistics are as follows;

Date of fires - early January 1994.

Cause of Fires - most were deliberately lit by arsonists.

Location of Fires - Most were within 250 km of the Sydney metropolitan
area, many being on the immediate fringes and in suburbs. A large number
were also on the far north coast of New South Wales. At least 136 separate
fires in total.

Damage - Dozens of houses, many millions of dollars, 4 human
deaths.

In firefighting, the firefighters place greatest emphasis on the protection
of lives and property. Loss of bushland itself is not regarded as a major
problem and thus large tracts are allowed to burn unchecked until houses
are approached. To control the fires a number of methods are used. In terms
of it's environmental effect, backburning is perhaps the most significant.
In backburning a controlled burn is lit from a given line (often the edge
of a property or house/s in a suburban street) so that the flames or fire
front burn towards the oncoming fire. In theory these two fires meet and
with nothing else left to burn the fire burns itself out. In some cases
around Sydney, including the 1994 Royal National Park fire, the fires resulting
from backburning actually caused more damage than the original fires they
were meant to combat.

A huge part of Kurringai Chase (including West Head) to Sydney's north
was burnt out as a result of the 1994 fires. Likewise for the National
Parks along Sydney's Middle Harbour, Port Hacking, parts of the Blue Mountains,
Lane Cove River National Park and Royal National Park. Over 90% of the
Royal National Park was blackened by the fires, making it the worst recorded
fire in its history.

The reason why these particular fires were so widespread and severe
are many. Some key reasons are presented below. Bushfires (mainly deliberately
lit) have been a part of Australian life since white settlement (and before).
It would be rare to go anywhere in Australia and see tree trunks that haven't
been blackened at some stage by bushfires. Contrary to popular belief the
bushland does recover after a bushfire, although how the recovery takes
place depends on a number of factors, including severity of the burn, plant
species in the area and presence or absence of grazing.

In and around Sydney most areas of bush, including the National Parks,
seem to have major bushfires about every 7 to 9 years. In the few areas
that get annual burn-offs, such as parts of Terry Hills (near the Belrose
end) that get so-called control burns most years in winter, the ground
cover build up is so minimal that there is little risk of major bushfire
ever occurring (those areas usually have a drastically altered wildlife
composition, reduction in species diversity and far more introduced weeds
instead of native grasses).

Having said the above, there was an unusually long gap in the periods
when many bushland areas including most National Parks around Sydney had
major bushfires and so the "fuel" build-up (dead leaves, etc.)
was greater than usual and hence the fires were greater in fury than usual.
For example, the last major fire in the western half of the Royal National
Park was in the late 1970's. The last major fire in the parts of Kurringai
Chase and Middle Harbour National Park that meet at Mona Vale Road was
about 1980. Thus these areas had been building up "fuel" for
over ten years. Excluding the summer of 1992-93 which was fairly typical
of Sydney and N.S.W. summers, the previous few summers (since 1988-89)
have been generally much wetter and cooler than usual. Thus there has been
much less opportunity for the bush to dry out and be conducive to burni
ng. Coupling this with the added growth over that time and drying this
summer (which has had more hot spells than usual) the fuel build-up is
much higher than usual and so the fires burn more severely. The only thing
that is difficult to explain is what prompted so many nutcases to go around
deliberately lighting fires during the hot weather. I can only guess that
once someone lights such a fire and it is reported in the media, others
with the same tendencies do likewise.

During the fire;

There are commonly reports of animals (including reptiles) dying during
bushfires. In mid-November 1974, Honorary Ranger Tony Butz found four adult
and one subadult Diamond pythons, Morelia spilota,
as a group when he was fighting a low intensity bushfire in a National
Park immediately adjacent to the Hawkesbury River north of Sydney. These
snakes were found moving away from the downhill moving fire front and were
believed to be fleeing the flames (Hoser, 1980).

Although many animals clearly die during bushfires, my own observations
lead me to believe that the mortality rate is nowhere near as high as most
people seem to think. Few, if any, species are usually wiped out from an
area (in the long term) by bushfires. There are a number of reasons for
this. Birds and mammals seem able to flee a fire front, being able to move
back as soon as it is safe to do so. Smaller animals that may not flee
the flames, such as reptiles and frogs, are able to hide away from the
heat in the tops of trees that may escape the flames, and in holes, rock
crevices, etc.. Although some animals clearly die in the flames, many don't
(Fyfe, 1980). am not aware of the publication of reptile mortality figures
for fires in percentage terms, but even allowing for a 75% mortality (which
I find unlikely) the ability of the remainder to repopulate the area is
clearly there.

I have attended bushfires in a number of areas, including around Sydney,
usually with a view to capture reptiles fleeing from the fire front. Surprisingly
few do! Clearly the majority go to ground and wait out the flames. Sydney's
bushland is well endowed with rocks, rock outcrops and other hiding spots
that would clearly be a safe haven from the flames, making the need to
flee a fire front less essential. I have observed
Spinifex (Triodia sp.) fires in relatively flat areas in
northern Australia and seen far more reptiles fleeing a given area than
in an area such as Sydney. One of the reasons is obviously the relative
lack of safe hiding places within the burning area. On my herpetological
travels I have noted that relatively flat areas burnt frequently are often
more devoid of reptiles than similar less frequently burnt areas, particularly
when there are large grazing mammals present. This is particularly true
for central and arid Australia. In early 1983
I noted that a burnt area just west of Shay Gap (Western Australia), along
the Goldsworthy Road, had far less herpetofauna than nearby unburnt areas.
However, what happens after the fire could be as important as the fire
itself.

After the fire;

After a bushfire there is far less ground cover and hiding spots for
small, cryptic animals such as reptiles. Thus, these animals become easy
targets for birds and other predators.

A week after a fairly severe bushfire in the Waterfall area of the Royal
National Park in the late 1970's I observed reptiles in the burnt out area.
What surprised me was how many there were. Numbers seemed to be as high
as ever. Due to the size of the area burnt, and the short time frame involved,
I discounted the theory that most of the animals could have migrated into
the area from outside, or had fled flames, returning immediately thereafter.
However, I did note a larger than usual number of birds of prey in the
area. Clearly the remaining reptiles had become an easy target for predators.
Perhaps more reptiles would die in the aftermath of the fire as a result
of becoming prey than during the fire itself? These features of bushfire
ecology need studying.

Even during the most severe of bushfires, including the one at Waterfall.
there are usually some areas untouched by the flames. This is particularly
so for hilly, rocky and wel1-watered areas, such as around Sydney. Winds
change direction, flames jump over a creek missing some of the border vegetation
and so on. All these areas represent a safe haven for the slowest and most
stupid of animals, in theory helping to ensure the survival of enough individuals
to maintain a population. Obviously, forest dwelling species can't survive
in an area denuded of trees (by a fire), but they can migrate back into
the area from adjoining suitable habitat, provided that the latter exists.
In terms of the recent bushfires in Sydney, that has become a problem.
Because some areas of bush are completely surrounded by densely populated
suburbs and the bush itself is virtually totally burnt out, the species
wiped out in these areas are unlikely to ever return. That is because there
are no "corridors" of entry. Fortunately for reptile lovers,
few if any reptiles will be affected in this way by the recent bushfires.
For some of the mammals, including some (now believed exterminated) Koala,
Phascolarctos cinereus, populations, the picture isn't as good.
Permanent local extinctions are likely.

Other notes;

The heat tolerance of many species is often underestimated. Again this
is an area in need of further research. In 1981 I burnt a spinifex bush
near Shay Gap (Western Australia). While the bush was in flames a previously
unseen adult male Ant-hill python, Bothrochilus
perthensis, appeared to move from-the frames in the bush to
where I was standing, some distance away from the heat of the flames. I
caught the snake and it was apparently unharmed and lived in captivity
without incident for some time before being stolen.

Similarly, I burnt a number of spinifex bushes
in the Newman (WA) area of Western Australia and Barrow Creek,
Northern Territory, and while finding lizards emerging from these bushes,
I was always surprised to see these animals often running through the flames
without apparent ill effects.

In late 1978, Ron Sayers and myself collected reptiles in the immediate
vicinity of a disused-railway line between Charters Towers and Townsville
(Queensland). The area was grassy with scattered trees, and a low intensity
grass fire was going through the area. We observed a number of Storr's
monitors, Varanus storri, running through the flames of the fire-front
without ill effect. This was usually in response to our chasing them around
the low rocky outcrops in the area.

In 1988 I spent three days attempting to catch a 2 metre adult male
Lace monitor, Varanus varius, that
had taken refuge at the top of a large tree in suburban Turramurra. Attempts
to smoke the lizard out of the tree were useless. On a number of occasions
flames and smoke have been used to extract reptiles from rock crevices
and logs. I have had no success in attempts to burn Cunningham's skinks,
Ergenia cunninghami, (Sydney sandstone form) and Sydney's Rosenberg's
monitors, Varanus rosenbergi, from rock crevices in the Dural area
of outer northwest Sydney. I did manage to smoke an adult Eastern
Brown snake, Pseudonaja textilis, from a hollow log between
Nevertire and Nyngan in western New South Wales. In that case it was clearly
the smoke running up the log, rather than the heat which made the snake
choose to flee.

After bushfires the vegetation clearly goes through a change in vegetation
regime. Some plants regenerate quickly while others take many years longer
to regenerate. As the vegetation pattern varies, so too does the reptile
composition. Around Sydney I've noted Bearded
dragons, Pogona barbatus, appearing to have a preference
for recently burnt bushland over adjacent unburnt areas. However, when
many hundreds of square kilometres are burnt at a time in one place, I
doubt that it would be possible for the local Bearded dragon population
to be able to significantly capitalise on their newly formed preferred
habitat.

Death Adders, Acanthophis antarcticus,
hiding in leaf and other ground litter would seem to be prime candidates
for high mortality rates in bushfires. However, they seem to survive in
reasonable numbers. In the case of this species this also seems to be dependant
upon two things. Not too frequent burning of the area and no grazing by
domestic stock such as cattle. Now that the West Head area has been severely
burnt for the first time in at least 15 years it will be interesting to
see the effect on local snake populations, including Death
Adders. Due to the extremely hilly and rocky terrain of the area
and the lack of grazing animals, I'd suggest that any long term damage
on numbers of this or other reptile species in the area as a result of
bushfires would be minimal. (Ed. note: in 1997 this was confirmed with
Death Adders being as common as ever in the area).

Grasslands in. parts of Northern Australia get burnt annually and yet
tree-dwelling reptiles such as Frilled Dragons, Chlamydosaurus kingi,
seem to survive in sufficient numbers each year. Rick Shine of the University
of Sydney has just completed a major study of this species. He presented
a paper on them at the recent (December 93 to January 94) Second World
Congress of Herpetology.